A spectroscope is a device that analyzes the spectrum of light emitted from a sample. A diffraction grating is one of the key components of the spectroscope. The performance of the spectroscope is determined based on the performance of the diffraction grating. The performance of the diffraction grating is determined based on the interval between grooves matching the wavelength of light to be analyzed, the precision of the interval, the reflectance of the light to be analyzed, and surface precision expressing the size of unevenness spots on the surface of the diffraction grating.
A diffraction grating for use in a spectroscope is manufactured by cutting off a metal piece with a ruling engine and an electron beam irradiation apparatus. It is unfavorable to manufacture the diffraction grating with such apparatuses since the introduction and maintenance costs of the apparatuses are required.
As a diffraction grating for use in a general-purpose spectroscope, a replica manufactured using a diffraction grating, which is manufactured with the method described above, as a master is used. The manufacturing method in which the replica is extracted from the master is suitable as a method for manufacturing the diffraction grating for use in the general-purpose spectroscope since the introduction and maintenance costs of a ruling engine and an electron beam irradiation apparatus can be reduced.
In recent years, nano-imprint technologies have been developed and applied to various products. The nano-imprint technology is a technology for transferring a microstructure having a size of several nanometers to several micrometers from a master to a replica or from the replica to the master. The nano-imprint technology is high in versatility in that it can be applied to various products. In addition, the nano-imprint technology includes a technology that allows cost reduction and mass production with automation. With the application of such a nano-imprint technology, it becomes possible to manufacture the replicas of diffraction gratings at low costs and in large amounts (e.g., Patent Literature 1 or the like).